As a quantity of wireless users and wireless data traffic sharply increase, a user imposes a higher requirement for a capacity and seamless coverage of a wireless network. To satisfy the user's requirement, an antenna form of an active antenna system (Active Antenna Systems, AAS for short) is widely applied to a communications industry.
Antenna elements in each column in the AAS can be connected to multiple power amplifiers. Therefore, multiple antenna ports can be separately formed in a horizontal dimension and in a vertical dimension. In addition, to ensure that a base station can flexibly provide better signal coverage for a user in a vertical direction, a drive network (a main function of the drive network is to map a vertical-direction antenna element onto an antenna port, so as to provide services for users in different scenarios by using different antenna ports) in which a downtilt and a beam shape can be flexibly adjusted in an automatic manner in a vertical direction is provided in the prior art. A structure of the drive network is:
      Q    =          (                                                  A              1                                            0                                                                                          0                                                                                                        A              k                                            0                                                                                          0                                              A              1                                                                                                                    A              k                                                            0                                              A              1                                            …                                0                                …                                0                                              A              k                                            …                                0                                                              α                1                            ⁢                              A                1                                                          …                                                              α                1                            ⁢                              A                1                                                                          ⋮                                ⋮                                                                                          ⋮                                                                                          ⋮                                ⋮                                                                                          ⋮                                ⋮                                                                                          ⋮                                                0                                0                                                                                                        A              1                                                                                                      0                                0                                                                                                        A              k                                                                          α                                  p                  -                  1                                            ⁢                              A                1                                                                                                                                                  α                                  p                  -                  1                                            ⁢                              A                k                                                        )        ,where Q is
a matrix including p×k block matrixes, p is a quantity of vertical-direction antenna ports in a column, and k indicates a quantity of optional drive network weighted candidates. Ai is a block matrix in the matrix Q and indicates that the block matrix is a weighting vector used to map z (z>=1) antenna elements onto one antenna port, and αi is a complex value weighting coefficient on the second antenna port. In this way, adaptive reference signals may be configured for the users in the different scenarios by selecting different columns in the drive network Q.
For example, a 3 Dimension Urban Micro (3 Dimension Urban Micro, 3DUMi for short) scenario in the 3rd Generation Partnership Project (3rd Generation Partnership Project, 3GPP for short) is used as an example. In the scenario, if a base station has a height of 10 meters, a building has eight floors, and each floor is three meters high, to ensure that all users in the whole building can be provided with good enough signal coverage, the base station may allocate a downtilt beam of 12 degrees to users in the first to the fourth floors whose heights are lower than that of the base station, and allocate a downtilt beam of −6 degrees (a downtilt beam projected upward from the base station) to users in the fifth to the eighth floors whose heights are higher than that of the base station: Therefore a drive network in the scenario may be designed as:
            Q      ′        =          (                                                  A              1                                            0                                              A              2                                            0                                              A              1                                                          A              2                                                            0                                              A              1                                            0                                              A              2                                                                          α                1                            ⁢                              A                1                                                                                        α                2                            ⁢                              A                2                                                        )        ,where A1 is a downtilt beam vector pointing to 12 degrees, and A2 is a downtilt beam vector pointing to −6 degrees. The drive network Q′ includes six different beams (each beam is corresponding to one direction and one width). Based on the six different beams in the drive network Q′, the base station may allocate, to users in different scenarios, reference signals corresponding to reference signals based on the different beams.
However, the inventor finds that when configuring a reference signal for user equipment (User Equipment, UE for short), a base station needs to send measurement reference signals corresponding to all possible configuration combinations in a drive network to the UE, to enable the UE to feed back corresponding channel quality information, so that the base station selects, from the possible combinations according to the channel quality information that is fed back, an optimal drive network configuration (that is, an optimal reference signal) and a measurement reference signal corresponding to the configuration. Specifically, Q′ is used as an example. A maximum of six antenna ports may be formed in Q′. When two antenna ports need to be formed, the two antenna ports are formed in a maximum of C62=15 possible drive network configuration combinations, and each configuration combination is corresponding to one to-be-sent and to-be-measured reference signal. Therefore, when there are plenty of combination solutions, reference signals and overheads of corresponding measurement and feedback are increased.